Elina competed in Bellator MMA, is the Former Cage Survivor Bantamweight Champion and has a Brazilian Jiu-Jitsu blue belt.
In her sophomore performance, she faced Anastasia Yankova on April 8, 2017 at Bellator 176, losing the bout via unanimous decision.
[7] After her two losses in Bellator as a teenager, Kallionidou finished her next two opponents since leaving in 2017, submitting Barbara Nalepka via bulldog choke at Ladies Fight Night 8,[8] and knocking out future UFC fighter Qihui Yan in the third round at WKG & M-1 Challenge 100.
[9] In her return performance, Kallionidou face Bruna Ellen on July 12, 2019 at Bellator 224, losing the bout in which she broke her hand via unanimous decision.
[11] After a year and half layoff, Kallionidou made her return against Petra Částková on October 1, 2021 at Bellator 267, submitting her opponent via heel hook in the first round.